A team of astronomers from Spain's Centre for Astrobiology has detected a sugar molecule called erythrulose in a cloud of gas and dust known as G+0.693−0.027, located about 27,000 light-years from Earth. The discovery, published in Nature Astronomy, provides new clues about how life's essential building blocks may have arrived on Earth.
What Was Found
Erythrulose is a four-carbon sugar found naturally in raspberries, melons, and self-tanning lotions. It is smaller than ribose, a sugar previously discovered inside an asteroid last year. The researchers used two powerful radio telescopes to detect the molecule's unique frequency as it spun and vibrated in the interstellar medium.
Dr. David Benoit, a molecular physicist at the University of Hull who was not involved in the study, told Metro: 'It is not uncommon to spot molecules in this part of space. But this is one of the first times this type of sugar has been found out there.'
Implications for the Origin of Life
The finding suggests that sugars can form in space without the presence of life, even before stars or planets form. This supports the theory that life on Earth may have originated from organic compounds delivered by meteorites. Erythrulose forms when two other organic compounds, glycolaldehyde and ethylene, clump together—a process aided by tiny dust grains that act as islands for molecules to congregate.
'Sugars are essential components of living organisms and thus finding complex organic molecules linked to life “building blocks” in space can help further explain where our chemistry comes from,' Dr. Benoit added.
How Much Sugar Could Have Reached Earth
Researchers estimate that up to 500,000,000,000 kg of sugar could have accumulated on Earth as it formed billions of years ago. This sugar may have triggered the chemical reactions necessary for life to emerge around 4.1 billion years ago, based on fossil evidence of ancient microbes. Other key building blocks include carbon, water, and nitrogen.
'A random combination of these could have ultimately led to primitive self-replicating systems,' Dr. Benoit noted.
Verification and Next Steps
The team repeatedly checked their results to confirm the detection, as finding a sugar molecule in space was unexpected. The discovery opens new avenues for understanding how organic molecules form in interstellar environments and how they might seed life on planets.
